categorise vs classify

categorise and classify both are verbs.

Word	Noun	Adjective	Verb	Adverb
categorise	No	No	Yes	No
classify	No	No	Yes	No

As verbs, classify is a hyponym of categorise; that is, classify is a word with a more specific, narrower meaning than categorise:

Other hyponyms of categorise include assort, class, separate, sort, sort out.

categorise (verb)	classify (verb)
place into or assign to a category	arrange or order by classes or categories
	assign to a class or kind
	declare unavailable, as for security reasons